The most used medicinal plants by communities in Mahaboboka, Amboronabo, Mikoboka, Southwestern Madagascar

Madagascar’s extraordinary biodiversity: Evolution, distribution, and use

Madagascar’s biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar’s past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique “living laboratory” for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth’s biodiversity.

Beyond the Bark: An Overview of the Chemistry and Biological Activities of Selected Bark Essential Oils

Essential oils have been used by indigenous peoples for medicinal purposes since ancient times. Their easy availability played an important role. Even today, essential oils are used in various fields—be it as aromatic substances in the food industry, as an aid in antibiotic therapy, in aromatherapy, in various household products or in cosmetics. The benefits they bring to the body and health are proven by many sources. Due to their complex composition, they offer properties that will be used more and more in the future. Synergistic effects of various components in an essential oil are also part of the reason for their effectiveness. Infectious diseases will always recur, so it is important to find active ingredients for different therapies or new research approaches. Essential oils extracted from the bark of trees have not been researched as extensively as from other plant components. Therefore, this review will focus on bringing together previous research on selected bark oils to provide an overview of barks that are economically, medicinally, and ethnopharmaceutically relevant. The bark oils described are Cinnamomum verum, Cedrelopsis grevei, Drypetes gossweileri, Cryptocarya massoy, Vanillosmopsis arborea and Cedrus deodara. Literature from various databases, such as Scifinder, Scopus, Google Scholar, and PubMed, among others, were used.

Drivers of population divergence and species differentiation in a recent group of indigenous orchids (Vanilla spp.) in Madagascar

With over 25,000 species, orchids are among families with remarkable high rate of diversification. Since Darwin's time, major advances attributed the exceptional diversity of orchids to plant-pollinator interactions. However, unraveling the processes and factors that determine the phenotypic and genotypic variation of natural orchid populations remains a challenge. Here, we assessed genetic population structure and floral differentiation in recently diverged leafless Vanilla species in a world biodiversity hotspot, Madagascar, using seven microsatellite loci and 26 morphometric variables. Additionally, analyses were performed to test for the occurrence of any patterns of isolation by distance, isolation by environment, and isolation by adaptation and to detect possible physical barriers that might have caused genetic discontinuities between populations. Positive inbreeding coefficients detected in 22 populations were probably due to the presence of null alleles, geitonogamy and/or some admixture (sympatric species). In contrast, the only high-altitude population showed an important rate of clonality leading to heterozygote excess. Genetic diversity was maximum in western populations, suggesting a postglacial colonization to the north and south. Clustering analyses identified seven genetic groups characterized by specific floral traits that matched five botanical descriptions in the literature. A contribution of montane refugia and river barriers on population differentiation was detected. We also detected combined effects of IBD/IBE and IBE/IBA on genetic differentiation and suggested this pattern is more likely determined by ecological isolation, although pollinator-mediated divergent selection could not be ruled out for some of the species. Overall, this study provides further insights on speciation in orchids, a group for which Madagascar shows one of the world's highest level of endemism and confirms the importance of the peculiar biogeography of the island in shaping species differentiation.

The Leafless Vanilla Species-Complex from the South-West Indian Ocean Region: A Taxonomic Puzzle and a Model for Orchid Evolution and Conservation Research

The pantropical genus Vanilla is a member of the Orchidaceae family, one of the largest and most diverse families of angiosperms in the world. It originated in America and differentiated in America, Africa, and Asia. About 132 species of Vanilla have now been accepted since the discovery of the genus. Within the Vanilla genus, leaflessness has appeared at least three independent times, in Africa, Asia, and America as an adaptation to drought conditions. The South-West Indian Ocean (SWIO) region, a biodiversity hotspot for orchids, is home to seven leafless species. Chloroplast markers failed to differentiate species within this recent SWIO clade. Morphological traits used for description are very similar between species and do not provide reliable identification. Moreover, some of the species have overlapping flowering periods and geographic distribution in Madagascar, increasing the probability of finding some sympatric species and, therefore, hybrids. Leafless Vanilla species from the SWIO islands are thus an excellent model for understanding the evolution of orchids. For their conservation, and to confirm the identity of these leafless species, an integrated approach with classical taxonomy using a large number of samples, intense fieldwork on biology and ecology, and molecular studies using variable markers is necessary.

Therapeutic potential of medicinal plants for the management of scabies

Sarcoptes scabiei (S. scabiei), a parasite mite which causes scabies disease resulting in serious public health concern. The long-term scabies disease can lead to complications such as septicemia, acute post-streptococcal glomerulonephritis, heart disease, and secondary infections. Timely treatment to the affected patients is required to control the disease and get rid of the causative agent. Delayed diagnosis and inappropriate treatment can lead to serious consequences. The most common treatment strategy is the use of allopathic medicines which can immediately relieve the patient but have the drawback of side effects. The safe and cost-effective alternative treatment strategy is the use of medicinal plants which have beneficial therapeutic potential against variety of diseases due to the presence of many bioactive phytoconstituents with no or minimal side effects. For the present review, the published articles describing scabies disease and its phytotherapeutic modalities were searched through different data bases including Google Scholar, PubMed, Medline, and ScienceDirect using the keywords like S. scabiei, prevalence of scabies disease, and phytotherapy of scabies. A large number of medicinal plants, such as Melaleuca alternifolia, Curcuma longa, Azadirachta indica, Rosmarinus officinalis, Capsicum annuum, Cinnamomum camphor, Solanum nigrum, and Eupatorium perfoliatum, have been reviewed for the promising future treatments of scabies. All the studied plants have many bioactive compounds with potential therapeutic effects against scabies and can be utilized for therapeutic purposes for this disease. This literature study has limitations because of the lack of sufficient data due to limited pre-clinical trials in this particular area. This review provides a baseline to explore the therapeutic potential of these medicinal plants against skin diseases. However, extensive studies are required to identify, authenticate, and characterize the bioactive compounds present in these plants which may lead to value addition in pharmaceutical industries providing the cost-effective way of treatment with minimal side effects.

Insecticidal and Antifeedant Activities of Malagasy Medicinal Plant (Cinnamosma sp.) Extracts and Drimane-Type Sesquiterpenes against Aedes aegypti Mosquitoes

The overuse of insecticides with limited modes of action has led to resistance in mosquito vectors. Thus, insecticides with novel modes of action are needed. Secondary metabolites in Madagascan plants of the genus Cinnamosma (Canellaceae) are commonly used in traditional remedies and known to elicit antifeedant and toxic effects in insect pests. Here we test the hypothesis that extracts of Cinnamosma sp. enriched in drimane sesquiterpenes are toxic and/or antifeedant to the yellow fever mosquito Aedes aegypti. We show that the bark and root extracts, which contain a higher abundance of drimane sesquiterpenes compared to leaves, were the most efficacious. Screening isolated compounds revealed cinnamodial to be the primary driver of adulticidal activity, whereas cinnamodial, polygodial, cinnafragrin A, and capsicodendrin contributed to the larvicidal activity. Moreover, an abundant lactone (cinnamosmolide) in the root extract synergized the larvicidal effects of cinnamodial. The antifeedant activity of the extracts was primarily contributed to cinnamodial, polygodial, and cinnamolide. Parallel experiments with warburganal isolated from Warburgia ugandensis (Canellaceae) revealed that aldehydes are critical for-and a hydroxyl modulates-insecticidal activity. Our results indicate that plant drimane sesquiterpenes provide valuable chemical platforms for developing insecticides and repellents to control mosquito vectors.

Ethnobotanical survey of medicinal plants in central Abyan governorate, Yemen

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicinal plant knowledge in Yemen is still only passed on orally from one generation to another. A few studies, mostly very limited in scope, have been dedicated to this indigenous knowledge so far. This paper presents the results of the first extensive field study in southern mainland Yemen, undertaken in three communities in the central region of Abyan governorate. The study is aimed to preserve the heritage of this indigenous knowledge and to explore and select local medicinal plants that promise high pharmacological efficacy for further pharmacological and phytochemical investigations.

METHODS

356 indigenous informants (273 males, 83 females) were interviewed about the modes of application and uses of the medicinal plants in the region. The ethnobotanical data were recorded by semi-structured face-to-face interviews, substantiated by specimen collections and taxonomic identifications and quantitative data analysis including informant consensus factor (ICF) and number of use-reports.

RESULTS

In total, 195 medicinal plant species (170 wild and 25 cultivated) belonging to 138 genera and 55 flowering plant families, were recorded for the treatment of 155 different ailments classified into 16 categories. Apocynaceae (25 species), Fabaceae (18 species), Euphorbiaceae (16 species) and Asteraceae (14 species) were the most frequently used plant families. Paste (86) followed by unprepared plant exudates (77) and decoction (55) were the most common herbal preparation modes. Dermal application (51.8%) was the most common administration route. The highest number of use reports and the maximum number of used medicinal plants were recorded for treatment of skin and gastrointestinal ailments. Forty-five species have never been reported in the ethnomedicinal literature before. Plant species with the most citations were Aloe vacillans Forssk. (malaria), Solanum incanum L. (tooth decay), Caralluma awdeliana (Deflers) A. Berger (diabetes), Tribulus terrestris L. (kidney stones), Aristolochia bracteolata Lam. (snake poison), Hydnora abyssinica A.Br. (stomach ulcer), Indigofera oblongifolia Forssk. (urine retention) and Chrozophora oblongifolia (Delile) A. Juss ex Spreng (haemorrhoids).

CONCLUSIONS

Significant traditional knowledge of the uses of local medicinal plant species was recorded for the first time for central Abyan in particular and southern Yemen in general. The study shows that the medicinal plants still play an important role in the primary health care in the study area. The ethnobotanical results provide a basis for further pharmacological, biological, pharmacognostical, and phytochemical investigations.

First ethnobotanical inventory and phytochemical analysis of plant species used by indigenous people living in the Maromizaha forest, Madagascar

ETHNOPHARMACOLOGICAL RELEVANCE

Characterized by one of the highest rates of endemism and biodiversity in the world, Madagascar provides a wide variety of medicinal plants, that could represent a potential source of new drugs. The main aim of this study was to investigate the potential medicinal properties of the plant species used by indigenous people in Maromizaha forest and to provide the first ethnobotanical inventory of the area.

MATERIALS AND METHODS

Data were collected through open semi-structured interviews with local informants, the reported plants were collected and identified to create a specimen herbarium. Informant Consensus Factor (ICF) was calculated for each ailment category mentioned in the use-reports. A selection of seven medicinal plants was submitted to phytochemical and antimicrobial analysis. The results were discussed and compared with those described in ethnobotanical and pharmacological literature.

RESULTS

One hundred and three villagers were interviewed and a total of 509 use-reports were recorded. Information on 117 plant species belonging to 57 botanical families were provided. 12 categories of indigenous uses were recognized, among them the higher ICF values were recorded for cardiovascular complaints (0.75), general and unspecific diseases (0.74), digestive disorders (0.69), and diseases of the skin (0.55). The traditional medicinal uses of 18 species (15 endemic) were described for the first time. In total, 22 different bioactive compounds were identified; polyphenols, monoterpenes, organic acids, and vitamin C were observed in the chemical composition of all the analyzed samples. Macaranga perrieri showed the highest values of both total polyphenolic compounds and antioxidant activity. Antimicrobial activity was observed in leaf and bark extracts of Dilobeia thouarsii.

CONCLUSION

These results confirmed the importance of investigating the traditional use of plant species, suggesting the crucial role of ethnobotanical studies for rural development, biodiversity conservation, and the sustainable use of plant resources in the studied area.

Plants used by the rural community of Bananal, Mato Grosso, Brazil: Aspects of popular knowledge

Studies in rural communities are important to maintain popular knowledge between generations, as well as to identify new species for pharmaceutical production. Thus, the objectives of this study were to determine which plant species the rural community of Bananal, Mato Grosso, Brazil, uses by calculating the levels of fidelity and concordance regarding species uses among residents and to determine if there is a relationship between the number of known useful plants and levels of education, age, and residence time. Ethnobotanical data was collected from residents of the community through semi-structured interviews in January/December/2016. Species diversity was calculated using Shannon-Wiener, Level of Fidelity (LF), Correction Factor, and the Percentage of Agreement regarding the Main Uses (AMU). Statistical tests were performed using generalized linear models (GLM) in the R environment. The plant use indications were grouped according to the International Classification of Diseases and Related Health Problems (ICD 10). We found 152 species belonging to 130 genera and 67 families. The most frequently used plant parts were leaves, and decoction was the most frequent preparation mode. Strychnos pseudoquina was the species with the highest amount of use indications. The diversity index was 4.5 nats/ind^-1. The body system with the most citations was the code XVIII of ICD 10, corresponding to the species: alfavaca, mentraste, terramicina, angelim, fedegoso. Medicinal species with AMU values higher than 25% were: Strychnos pseudoquina, Plectranthus barbatus, Citrus sinensis cv. pera, Cymbopogon citratus. There was a relationship between the number of useful plants and the residence time of the participants. The Bananal community revealed high species richness and the relationship of knowledge showed that the older the residents and the longer their residence time in the community, the more knowledge they acquired.

The role of endemic plants in Mauritian traditional medicine - Potential therapeutic benefits or placebo effect?

ETHNOPHARMACOLOGICAL RELEVANCE

The Mauritian endemic flora has been recorded to be used as medicines for nearly 300 years. Despite acceptance of these endemic plants among the local population, proper documentation of their therapeutic uses is scarce. This review aims at summarising documented traditional uses of Mauritian endemic species with existing scientific data of their alleged bioactivities, in a view to appeal for more stringent validations for their ethnomedicinal uses.

MATERIAL AND METHODS

A comprehensive bibliographic investigation was carried out by analysing published books on ethnopharmacology and international peer-reviewed papers via scientific databases namely ScienceDirect and PubMed. The keywords "Mauritius endemic plants" and "Mauritius endemic medicinal plants" were used and articles published from 1980 to 2016 were considered. 675 works of which 12 articles were filtered which documented the ethnomedicinal uses and 22 articles reported the biological activities of Mauritian endemic plants. Only materials published in English or French language were included in the review. Available data on the usage of Mauritian endemic plants in traditional medicine and scientific investigation were related.

RESULTS AND DISCUSSION

We documented 87 taxa of Mauritian endemic plants for their medicinal value. Endemic plants are either used as part of complex herbal formulations or singly, and are prescribed by herbalists to mitigate a myriad of diseases from metabolic disorders, dermatological pathologies, arthritis to sexually transmissible diseases. However, these species have undergone a limited consistent evaluation to validate their purported ethnomedicinal claims. As the World Health Organization Traditional Medicine Strategy 2014-2023 emphasises on moving traditional medicine into mainstream medicine on an equally trusted footage, the re-evaluation and modernization of Mauritius cultural heritage become necessary.

CONCLUSIONS

With a consumer-driven 'return to nature', scientific validation and valorization of the herbal remedies, including efficacy and safety are, therefore, important. This review reports the scarcity of research on validating the efficacy and safety of medicinal endemic plants. This calls for the use of optimised methodologies to investigate the claims of therapeutic effects resulting from the use of these traditional medicines.

Human-Forest interfaces in Hugumburda-Gratkhassu National Forest Priority Area, North-eastern Ethiopia

BACKGROUND

Traditional management regimes and knowledge systems of forest resources have shaped forests throughout the world where materials from individual species are harvested in a sustainable manner. To comprehend this, the vegetation of Hugumburda-Gratkhassu Forest was described and related to anthropogenic factors.

METHODS

Three ethnobotanical research methods were used to collect indigenous knowledge of the local inhabitants related to conservation and utilization of forest resources. Direct matrix ranking was conducted to discover local attitudes on species preference for multiple use. During this work, the 46 most important tree and shrub species were selected based on recommendations of local guides and key informants to determine the range of uses obtained from each species. Through paired comparison, activities supposed to be the major cause of degradation of the forest were adopted. Pairs of activities were then established from the relation n (n-1)/2. Each respondent was then asked to select an activity that he considered being a major problem to management of the forest. Semi-structured interviews were used to obtain information from sixty local informants to address community attitudes towards forest management and utilization.

RESULTS

The result obtained from direct matrix ranking showed; that 20 out of 46 plant species compared had the highest scores and rank, indicating that these species are the most important and are exploited by the local communities for multiple purposes. The paired comparison exercise revealed logging for construction materials to be the major threat to the forest due to cutting of large volume of wood for construction of churches, health centers, schools and new houses. Juniperus procera, Olea europaea ssp. cuspidata, Rhus glutinosa, Ficus sur, Hagenia abyssinica, Cassipourea malosana and Acacia etbaica were the most selected and exploited plant species for these purposes.

CONCLUSIONS

Survival of protected areas depends on the support of local communities, rather than on fences, fines, or even force. The local communities in the study area have a rich indigenous ecological knowledge to suggest appropriate solutions for improvement of the forest resources. Thus the old tradition of isolating forests from the community has to be avoided and the basic needs and traditional rights of the communities over the uses of forest resources should be recognized.